We seek renewal of the Case Western Reserve University (CWRU) Nephrology Training Program, which has been funded continuously for twenty-fouryears. Our goal is to train promising postdoctoral fellows who are committed to understanding normal kidney function and the pathogenesis of kidney disease as independent investigators . Support is requested for three postdoctoral, board-eligible or board-certified internists and/or pediatricians, or basic scientists (Ph.D., M.D. or M.D./Ph.D.) for two or more years of research training. Normally, 1-2 new trainees enter the program each year. The principal training mechanism is performance of research under the supervision of one or more of the primary trainingfaculty. This group is highly interactive and collaborative, and consists of 14 investigators in the adult or pediatric Divisions of Nephrology and 17 other clinical and basic scientists, all of whom actively study kidney biology and disease. The training faculty are based in six departments, Medicine, Pediatrics, Pathology, Physiology, Pharmacology and Epidemiology/Biostatistics at the School of Medicine. Research interests of the primary faculty include glomerular development and disease, epithelial cell biology and ion transport, genetic epidemiology, health services research and clinical trials. Research faculty apply cellular, molecular biological, genetic, genomic and epidemiological methods to in vitro models, animal models and/or patients. Faculty laboratories contain over 20,000 square feet of state-of-the-art space. The resources of the CWRU Clinical and Translational Collaborative are available for patient-oriented research. Training also includes lectures, weekly seminars and, if appropriate, course work (formal degree programs or individual classes). Trainees frequently present their work in local seminars attended by faculty and other trainees as well as at national meetings. Career mentoring is an integral aspect of the program. A formal mechanism of administration, governance and program evaluation is in place to assure program quality.This program offers nephrology and basic scientist postdoctoral fellows an interdisciplinarytrainingprogram in state-of-the-art experimental approaches to define normal kidney physiology and mechanisms of disease within the rich, research environment of the CWRU School of Medicine. RELEVANCE (See instructions): The prevalence of end stage renal disease is approximately 1500 per million population in the United States and approximately 2 to 3% of the U.S. population has abnormal kidney filtration function. Prevalence of CKD in the United States in 1999-2004 is higher than it was in 1988-1994. Trainees supported by this program will develop into independent investigators focused on reducing kidney disease burden in theU.S.